The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In the paper discussed results of investigation of increasing of shape passableness and adaptability to terrain for walking machines and robots with cyclic movers types. Usage of cyclic walking movers allows not to care about gait safety and stability and exclude the necessity in controlled adaptation system. By the other hand, strict trajectory of support points of cyclic type of walking mechanisms...
This paper extends the longitudinal walking controller of biped robots proposed by one of the authors to walking along a smooth curved path. The previous controller defined in a fixed inertial frame is redesigned with respect to a moving frame attached to the center of mass (COM) of the robot in order to achieve walking along an arc. As a result, it is found that a desired position of the zero-moment...
This paper discusses the resolved viscoelasticity control (RVC) method that explicitly considers the structure-variability for a humanoid. In a previous report, the author proposed resolving the virtual viscoelasticity at the center of gravity into the joint viscoelasticity considering redundant degrees of freedom, and named this method as RVC. However, the author considered only the single support...
This work introduces a novel hybrid control architecture for a hexapod platform (Weaver), making it capable of autonomously navigating in uneven terrain. The main contribution stems from the use of vision-based exteroceptive terrain perception to adapt the robot's locomotion parameters. Avoiding computationally expensive path planning for the individual foot tips, the adaptation controller enables...
As legged robots maneuver over increasingly complex and rough terrains, designing motion planners with the capability of predicting future footsteps becomes imperative. In turn, these planners provide a valuable tool for understanding the fundamental principles underlying human locomotion [2, 3]. In this study, we use our previously proposed phase-space planning framework [1] to analyze human walking...
This paper introduces a novel control system of bipedal robots on uneven terrain. Since this method does not require to measure Zero Moment Point (ZMP), the tracking performance of the controller is not deteriorated by the noise on a measured ZMP. Moreover, the robot withstands frequent perturbations because of its two-degree-of-freedom structure. The robot is stabilized by Center of Mass (COM) regulation...
In order to combine the advantages of both wheeled robot and legged robot, a multi-motion mode wheel-legged hexapod robot is designed. The robot can change motion mode to stable walking or fast skating. The design principle of the wheel-legged hexapod robot is introduced. The kinematics of swinging legs and supporting legs are analyzed independently. The tripod gait of the robot for walking is planned...
In this paper, we show an underactuated bipedal walker can travel on steep slope by bending its stance knee when the swing foot hits on the ground. First, we introduce an underactuated bipedal model with knees which can be controlled knee angles by applying the control input. Second, we consider an input-output linearization formula with three desired time trajectory functions and output-following...
Inspired by gecko's movement characteristics, we proposed a gecko inspired climbing robot, which is based on the GPL (Gecko inspired mechanism with a Pendular waist and Linear legs) model. In this paper, further research is made to analysis its gait and continuity. We optimist the driving angle to maintain the cyclical movement. Furthermore, the issues related configuration and motion planning are...
The zero moment point (ZMP) control method is usually used in stable biped walking. A novel preview control of ZMP is proposed in the paper. First, the dynamics of a biped robot is modeled as a running cart on the table which gives a convenient representation to treat ZMP. Second, the walking pattern generation process is describes in details and a presented preview controller is introduced to reduce...
In the foot trajectory planning of quadruped robot with active variable stiffness of flexible joint, the existence of the flexible joints makes quadruped robot legs oscillate in swing phase. In this case, this paper proposes a joint stiffness coefficient adjustment strategy and a new foot trajectory generation method. Simulation experiments show that this method can effectively reduce the volatility...
The purpose of this paper was to extend a landing force control method on the flat terrain proposed by Y.D Kim etc. [1] to absorb the impulsive ground reaction force for biped robot stable walking on the slope. Firstly, the swing foot and the terrain are modeled as two three-ports network systems that are connected respectively, and exchange energy with each other. Secondly, the impulsive impact of...
Real-time detection of gait events play a vital role in movement dependent control applications such as rehabilitation for lower limb amputations. It also helps in determination of spatio-temporal and kinematic parameters. Gyroscopes, inertial sensors, magnetometers and foot sensors are popular in the detection of gait events. They need to be mounted carefully, or foot should be placed specifically...
Animals are able to accelerate rapidly from rest with incredible dexterity but these transient motions are poorly understood. Here we present the first examination of the time optimal behaviour of a quadruped sprinting from rest. We develop a planar multi-body model and employ modern trajectory optimization methods to produce a motion without prescribing periodicity or foot contact order. Our trajectories...
The design of legged robots is often inspired by animals evolved to excel at different tasks. However, while mimicking morphological features seen in nature can be very powerful, robots may need to perform motor tasks that their living counterparts do not. In the absence of designs that can be mimicked, an alternative is to resort to mathematical models that allow the relationship between a robot's...
In this paper, we propose a real-time control method for skating motion of humanoid robots. There are three problems for skating motion: (1) keeping dynamic balance, (2) adequately controlling foot force to suppress slipping at the foot, (3) controlling full-body motion in real-time. For solving these problems, we propose the Skating Motion Generator and the Skating Motion Stabilizer. In the Skating...
Common design principles for low cost humanoid robots include a low center of mass height and a large support area for increased static stability. However, such principles limit the bipedal mobility of the robot due to the kinematic constraints involved. In this paper, we present an efficient locomotion controller that utilizes automatically calculated heel and toe lift motions to overcome the kinematic...
In this paper, we address the problem of planning optimal zero moment point (ZMP) trajectories for the double support phase in bipedal gaits that alternate between single and double support. This is achieved by allowing pre- and post-actuation during the single support phases. Thus, we solve two coupled problems: exact tracking of a given desired ZMP trajectory in the pre- and post-phases (single...
While numerous gaits in the horizontal regime (e.g. walking or running) have been defined for legged systems on level ground, no dynamically grounded definitions have been developed for dynamic vertical running. Gaits have clear implications to robotic control strategy, efficiency, and stability. However, while several climbing robotic systems have been described as achieving ‘running’, the question...
To enable robust dynamic walking on the Atlas robot, we extend our previous work by adding a receding-horizon component. The new controller consists of three hierarchies: a center of mass (CoM) trajectory planner that follows a sequence of desired foot steps, a receding-horizon controller that optimizes the next foot placement to minimize future CoM tracking errors, and an inverse dynamics based full...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.